Silicon carbide devices comprise a high breakdown field strength, which is similarly high as the maximal tolerable field strength in thermally grown silicon dioxide, due to the large band gap. At the semiconductor surface of silicon carbide devices (e.g. at the edge termination), very high electrical fields can occur, which represent high stress at least for the passivation layers. For example, electric fields in the range of more than 1.5 MV/cm can occur at the edge region of silicon carbide device implementations so that a passivation with a material comprising good breakdown resistance like polyimide (>3 MV/cm) may be required. However, a polyimide passivation may gather moisture, which may cause corrosion of the silicon carbide.
Therefore, a passivation taking into account high electric fields and moisture is important for the breakdown behavior and the long-term reliability of silicon carbide devices.